The present invention relates to a bis(aminostyryl)naphthalene compound, a synthesis intermediate thereof, and a process for production thereof, the naphthalene compound being suitable for use as an organic luminescent material which emits light of desired color.
Organic electroluminescent elements (EL elements) nowadays are attracting attention as a component suitable for flat panel displays emitting light spontaneously, responding at high seeds, and being independent of viewing angles. This has aroused attention to organic luminescent materials as a constituent of EL elements. One advantage of organic luminescent materials is that they have desired optical properties according to their molecular design. Therefore, it is possible to produce luminescent materials emitting any of three primary colors (red, blue, and green). Combination of these luminescent materials will realize full-color organic electroluminescent elements.
A bis(aminostyryl)benzene compound represented by the general formula [A] below emits intense light of color from blue to red in the visible region depending on substituents introduced therein. Therefore, it will find use in various applications, not limited to use as a material for organic electroluminescent elements. It is capable of sublimation and hence it offers the advantage of forming a uniform amorphous film by vacuum deposition. At present, it is possible to predict to some extent the optical properties of a material by means of molecular orbital calculations. However, it is most important to develop a process for efficient production of a material necessary for practical use. (where Ar denotes an aryl group which may has a substituents, and Ra and Rb may be identical or different, each denoting a hydrogen atom, saturated or unsaturated hydrocarbon group, aryl group which may have a substituent, cyano group, halogen atom, nitro group, trifluoromethyl group, amino group, or alkoxyl group.)
A large number of compounds represented by the general formula [A] have been produced so far as the organic luminescent material. Most of them emit light of blue to green, and a few of them emitting yellow to red light have been reported. [Institute of Electric Information and Communication, Report on Technical Researches, Organic Electronics, 17, 7 (1992); Inorganic and Organic Electroluminescence 96 Berlin, 101 (1996); etc.] Any process for their efficient production has never been established.